Many consumer products are packaged in granular or powdered form, such as for example, nutritional products, infant formula, flour, coffee, and sugar. Granular or powdered products which are sold in volumes larger than one-time use amounts require specific packaging. The packaging must be suitable for transportation and storage until first-time use by a consumer and must subsequently provide adequate storage for the consumer between uses. Adequately storing the product throughout the consumption period of the volume of powder requires packaging which prohibits waste and contamination, is strong and durable, and is convenient to the user.
Large volume consumer powdered products have been conventionally offered in a paper cylindrical package with a plastic peel-off lid. Powdered manufacturers have recently looked to new and innovative containers for many reasons, including durability, contamination, manufacturing waste, and consumer waste. The container must also be suitable for long-distance trailer and cargo container shipping. For example, the container must be acceptable for packaging, shipment and storage at a variety of elevations.
Packaged products will encounter air pressure differentials associated with elevation gains and losses as they are distributed. When containers are sealed, the containers trap the surrounding environment inside the container. For example, a container sealed near sea level will have an air pressure that is greater than the air pressure at higher elevations. When that container is distributed to a high elevation location, the greater air pressure in the interior of the container will applies interior force to the container. Depending on the container design, contents, headspace volume, etc., this pressure differential may negatively affect the container by deforming its shape or causing seal integrity issues. The opposite reaction happens when a container is sealed in a high elevation location because lower air pressure is trapped inside the container. When that container is distributed to a near sea level location, the greater air pressure in the outside environment applies exterior force to the container. This pressure differential may negatively affect a plastic container appearance, such as for example, by causing paneling. For example, a plastic walled container may bow in or bow out to a noticeable amount.